Such devices are used especially in the area of laser and high-frequency surgery, which are intended to effectively remove fumes and viruses or bacteria generated during surgery in the area of operation. To achieve this, a suction snorkel, which is attached to a suction line, is held in the immediate vicinity of the laser scalpel, so that the harmful substances generated are immediately removed and retained in a filter device. To do so, a preliminary filter for retaining suspended matter or aerosol particles, which is followed by a larger bacteria and odor filter on the inlet side to the extraction fan, is usually inserted in the suction line.
Such a device has become known from German Offenlegungsschrift No. DE-OS 41 21 069. The filter inserts located in the suction line are arranged either at the end of the suction line, if necessary, downstream of a preceding liquid trap, in which case a rather long section of the suction line is exposed to unfiltered, contaminated intake air, or the filter is arranged, to the extent possible, at the front of the suction opening. In the latter case its ease of handling is, however, compromised, so that it must have a large volume, as a result of which its separation capacity is low.